1873.] 



DK. J. E. GRAY ON THE TRIONYCHID.«. 



53 



Trionyxl peguensis, Gray, Suppl. Cat. Sh. Rept. p. 99 ; Ann. & 

 Mag. Nat. Hist. 1872, x. p. 337. 



Hab. India (Pegu, Theobald's coll.). 



5. Landemania. 



Landemania, Gray, P. Z. S, 1869, p. 212 ; Suppl. Cat. Sh. Rept. 

 p. 96. 



Skull tapering in front ; nose short ; space between the square 

 nose-hole and the orbit about half the diameter of the latter ; the 

 palate with a rather elongated, somewhat broad, deep concavity from 

 the front to the internal nostrils, which are nearly on a line with the 

 front end of the zygomatic cavity ; alveolar surface gradually becom- 

 ing wider and broader on the hiuder part of the sides. Lower jaw 

 much produced in front, contracted on the sides, with a deep conca- 

 vity on the upper surface, which is very long. Hinder part of the 

 sides with a deep concavity ; edge with a convexity on the inner side, 

 and a deep ridge on the outer side. 



Length of skull 2\ inches; width If inch. 



The skulls from different specimens from China vary considerably. 

 The nose in some is longer than in others ; they show a gradual 

 passage in this respect. The length of the under jaw shows a similar 

 variation. In two of the specimens the front of the alveolar surface, 

 which is deeply concave, is smooth ; but in the other, which was from 

 the half-dried specimen of Landemania irrorata, there is a slight in- 

 dication of a central longitudinal keel. The hinder part of the alve- 

 olar surface on the side is not quite so concave ; but I see no other 

 appreciable difference. (See fig. 6.) 



Fig. 6. 



Landemania peroccUata. 



The genus Landemania was first described from a specimen that 

 had been dried before it was placed in spirit ; and the rugosity on 

 the surface is very slight, if not produced by accident. At any rate, 

 I think it wants confirmation. I believe, after comparing its skull 

 with the skull of Triony.v perocellatus, also from China, that it is 



